Alternating cttkbent cibcutt controlling mechanism



Oct. 13, 1931. F. w. LEE ET AL 1,826,894

ALTERNATING CURRENT CIRCUIT CONTROLLING MECHANISM g ""1" "F- 3; HQ E FREDERICK w. LEE MYmck W. PULLEN Oct. 13, 1931. F. w. LEE ET AL 7 1,326,894

ALTERNATING CURRENT CIRCUIT CONTROLLING MECHANISM Filed June 9, 1927 :5 sheets-sheet Irwentor F I G \0 FREDERICK W. LEE & MYRIGK W. PULLEN Patented Oct. 13, 1931 UNE'EE. STATES PATENT OFFECE FREDERICK W. LEE, OF OWINGS MILLS, AND MYRICK W. PULLEN, OF TOWSON,

MARYLAND ALTERNATING CURRENT CIRCUIT CCJNTROLLING MECHANISM Application filed June 9,

This invention relates in general to alternating current switches and more particularly to the breaking and establishment of periodic and alternating current circuits without the formation of objectionable transient eifects.

It is a well known fact to those familiar with the art that transients and other disturbances may arise when a current is made or interrupted at a certain specified point or time of a cycle. This interruption of current may cause the liberation of too much energy at the point of interruption causing great damage to the switching or other apparatus,

and besides it may cause the formation of objectionable transients in adjacent circuits. On the other hand, when the circuit is closed there may be caused sudden rushes of current and an accompanying transient which may be as objectionable as when the circuit was suddenly interrupted. These objectionable transient conditions resulting from the breaking or making of the circuits at instances other than when the current value approaches zero also seriously interfere with radio reception and in these present days where everyone is desirous of obtaining radio reception which is free from all disturbances, it has become important to provide switching gear which reduces to a minimum the formation of objectionable transients and other disturbances in adaccnt circuits.

All alternating current circuits have, in a sequence of a period, instants at which the current passes through zero, or in other words, instants when there is no current whatever in the circuit. If the current should be interrupted at either of those points of zero current flow there would be entailed no arcing at the contacts and no disturbances in the circuits. The establishment or interruption of the circuits at those instants of zero current value is especially important in connection with sign boards, alternating current motors and other control circuits wherein are involved repeated arcing at the contact points. This arcing causes a rapid wear upon the contact points and it is accordingly among the objects of the present invention to elim- 59 inate this arcing by providing means for 1927. Serial No. 157,750.

opening or closing the circuit as the case may be, at or near the point where the current passes through zero. The attainment of this object is of especial importance in the case of a sign flashing apparatus which usually con- 5 sists of a large number of circuits all of which must be interrupted at various intervals of time and in a definite sequence.

A further object of this invention is the provision of a synchronously operated master contact maker or breaker arranged to establish or interrupt a number of circuits simultaneously or in succession, as for example, the circuits in a sign flashing apparatus, the establishment or interruption of the circuit 5 being had without experiencing that objectionable arcing above referred to or the setting up of disturbing transients in the system.

A still further object of the invention is the provision of means for permitting the transference of one or more circuits to a single circuit maker or breaker operating at a specified time. Upon completion of this operation the circuit is transferred away from this circuit maker or breaker and another circuit (or circuits) is treated in the same manner such that the use of a separate mechanism operating synchronously for each circuit to be controlled is obviated.

A still further object of the invention is the provision of means for operating one or more master contacts together or separately from the same master contact operator, thereby permitting a plurality of master drums to be connected in multiple to the same synchronous operating mechanism.

A still further object of the invention is the provision of auxiliary control circuits for maintaining the master contactors either closed or opened for definite periods of time.

In this particular application there is illustrated one type wherein the circuit is held open for a definite length of time after which the contact again closes. Another arrangement may be had wherein the contact is held open normally and then closed at or near a definite point on a cycle for a given length of time.

A still further object is the provision of a more or less rigid system for directly and positively operating the master contact, there being entirely absent in this arrangement any intervening mechanism which may have appreciable time lag causing uncertainty and delay in action.

Other objects of the invention will appear more fully hereinafter.

T he invention consists substantially in the ionsrruct n location and relative arrangement of parts, all as will be more fully hereinafter set forth, as shown in the accompanying drawings, and finally pointed out in the appended claims:

Referring to the accompanying drawings:

Figure l is a partly perspective, partly sectional and partly diagrammatic View of an arrangement embodying the principles of the yention; for controlling a sign flashing apparatus.

Figure 2 is a side elevational View of the synchronously operated mechanism for controlling the master contact making and breaking device;

Figure 3 is a top plan View of the mechanism shown in Figure 2;

Figure l is an enlarged side elevational view of the lock open coils and interlock contact for shortcircuitin the trip coils;

Figure 5 is an enlarged top plan View of the synchronously operated breaker mechanism;

Figure 6 is a partial front view of the op erating disc showing the relation between trip pin trip pin release and trip pin release actuating lJflI;

Fi ure 7 is a diagrammatic View of the several circuits showing their relation to the controller drum, which latter is shown in development plan section; and

Figures 8, 9 and 10 are diagrammatic views showing respectively the several circuits which are sequentially established for controlling any one circuit.

Referring more articularly to the drawings:

As has already been indicated the particula arrangement herein illustrated has to do 1 par-ncularly with the control of sign fiashappara us, but it is to he understood that the princip f 4 re invention are equally applicable for use in controlling any other mechanisms or devices wherein it is desired to reduce to a minimum hose objectionable conditions which are occasioned by arcing at the contacts when t e latter are either opened or closed. In particular instance there is no p ase shift between the current and the volt" e due to the fact that incandescent lamps have .tantially unity power factor, and accordingly a synchronous motor or some other synchronous operator with a constant phase adjustment once will serve the purpose for making or bre king the circuit definite point on the cycle at n of the alternating current wave. If the power factor he not constant the synchronous operator may be made to compensate for phase in any desired manner.

Referring now to the drawings and more particularly to Figs. 2 and it will he soon that the synchronous operator 10 (in this instance preferably a synchronous motor) is connected to the circuit Z through which current is supp-lied to the controller drum ll (see Fig. 1) this drum being operable to intermittently establish the circuit through one set of lamps or another. The lamps are designated generally by the reference numeral 12, it being understood of cool that devices, other than lamps, may be C011 rolled with equal facility in the manner and by the mechanisms to he hereinafter described.

T his controller drum 11, which is a:- ra d for rotation about its shaft 13, is pro y' at either end thereof with annular conductor rings 1% and 1.5. Longitudinally spaced a ong the surface of the drum ll and electri .lly connected to the conductor ring; 14 are two sets of main contact bars 16. which latter may be of vary lengths for operating the several lamps 12 in intermittent order as may be desired. These two sets of main contact bars 16 are indepcni'lent of each other but are both connected to the conductor ring l l. Disposed between the several main contact bars 1 3 of each are a plurality of transfer contact bars ll", all of which are electrically interconnected with each other and with the conductor r n Two such sets of transfer contact oar are employed, one for each set of main contact bars 16 so as to provide a train tact bar for each main contact bar. right of the conductor ring are a nn a ity of circumferontially spa-1,, d cor. d cuit contact bars 18, all of these control bars being ele 'iricall connected to each other and to the conductor ring 14. It will he noticed that each main contact har 16 and its cooperating transfer contact l a 17 are rranged in such manner that the latter tends circuinferentially in opposi e retions from the line which is coincident with the end of the former. and it will be further noticed that each transfer contact har bears the same circumferential relation with respect to its cooperating control circuit contact bar 18.

Arranged to one side and extending longitudinally of the drum 11 are a plurality of contact fingers designated generally hy tho reference numeral 19. Of these fingers it will be seen that the extreme left hand finger 20 is constantly .in electrical contact with the conductor ring ll while the finger 91 to the left of the extreme right hand finger is constantly in electrical contact with the conductor ring 15. Between the fingers Q0 and 21 are alternately arranged the main contact fingers 23 and the transfer contact fingers 24. The extreme right hand finger 22 may be designated the control circuit contact finger. It will be seen. that as the drum 11 rotates in the direction of the arrow an initial circuit A will be established leadingfrom one terminal of the main power supply switch 25 through the linger 20, conductor ring 14:, main contactbar 16, main contact finger 23 and its associated bank of lamps 12 back to the opposite terminal of the switch 25. If the main contact bars be of equal lengths and if the ends be arranged such that they lie between parallelly extending lines the several amps will be operated simultanel-lowever, if the bars 16 be of varys, as is the case here, the several of lamps will. be operated during vary- .tervals of time, depending upon the long ..5 of the bars 16 and their relative cir cumferential positioninent about the surface of the drum 11.

New, in the absence of any further ovisions, when the main contact linger 23 leaves its associated main contact bar 16, arcing would occur with the result that the contact fingers, as well as the contact bars would soon be damageo at the same time that the objectionlble transients above referred to would occur in the associated circuits. To overcome this objectionable condition, the transfer bars 17 and the control circuit contact bars 18 have been provided for transferring the circuit away from. the main contact bars 16 in such manner that objectionable arcing conditions at the contact points are substantially eliminatc-d. How this is accomplished will ap pear more fully hereinafter.

Referring now to Figures 1, 2 and 3, it will. be seen t-l at the synchronous operator 10 is connected through an adjustable coupling device to a shaft 27 upon which is fixed a substantially circular disc 28. This shaft 27 is supported for rotation between two upright standards 29 between which the operr e disc is rotatable. The ad ustable coupi device 26 comprises a member 30 fixed to the shaft of the synchronous operator 10 and in turn suitably secured in an ad ustable 'n'ianner to a member 3l'iixed to the shaft 27.

e member 81 is provided with a circumential scale and the member 30 with an inlet 33 whereby to facilitate setting the mechanism to operate at any point in the current cycle.

Arranged adjacent the peripheral edge of the operating disc 28 for projection transicrsely therethrough, is trip pin 84, the rear end 35 of which is of reduced cross section. This pin is normally urged transversely the operating disc 28 by a coil spring d within a boss 37 arranged on the rear of the disc, this spring 36 surrounding the reduced portion 35 of the pin. Piv oted upon the boss 37 as at 38, is a trip pin use ide release member 39 arranged to seat within a. notch or groove 40 in the reduced portion 35 of the pin in such manner as to maintain the pin in retracted position. The member 39 is maintained normally in engagement with the notch 40 by the sole action of gravity although any other means may be employed for maintaining this member sea-ted within said notch. Located immediately in front of the operating disc 28 is a vertically extending ramp ll, the upper end ll of this ramp being of substantially arcuate shape and inclined with respect to the vertical plane of the front face of the disc 28. The relative arrangement of the inclined areuately shaped portion of the ramp 41 and the disc 28 are such that when the pin 34; is in projected position and the disc is rotating the ramp will operate to force the pin back into retracted position.

Extending transversely between the upright standards 29 and spaced vertically above the upper edge of the operating disc 28, is a stub shaft 12 upon which is l 'eyed a bell crank lever 48. Immediately adjacent th s bell crank lever and arranged to rotate n the stub shaft 42, is a substantial- "really estenc main contactor arm 4%, ti is arm 4A being maintain d in substan tially up t p ion by means of the tension spring inc tension of this spring ma be in any suitable manner. The hl crank lever 4-3 is provided with a collar 46 having upstanding lug l7 arranged to engage a pin 48 projecting from one side the @ne branch 4-9 of tcre 11k 1 e v r 3 extends downwardly and path of rote on of the trip pin 3-4. when the latter is in projected position, while the other tad shorter branch 50 of th (1' 48 has connected loosely thereto as at 51, dependin reset rod 52. The fun tion of this reset rod 52 w be set forth hereinafter.

Mounted. in suitable manner above the operating disc 2 but extending preferal'ily across the free upper ends of the uni ght supports 29, is a panel 53 of insulati I material upon which are mounted a pair of laterally sp fired circuit breaker contact points 54. The free upper end of the main contactor arm 44 has insulatingly mounted thereon a brn ng member 55 adapted to i.terconnec tie c cnit breaker contact points 54; when the i in 44; is pulled to the right Fig. l) by the spring 4,13. One of the contact 54 is electrically connected to one of the tcrinir inafter, are arranaed to actuate a keeper 57 pivoted as at 58 upon the supporting member 5 coil spring 60 normally maintains -aid l" in inoperative position. The

contactor: i

7 further provided with a contact point 63 in- Slllll. ed upon the supporting he so for th. 56. The terminal of one of the solenoids 56 is electrically connected to the c cnit contact finger 22 while the oppo nna of the solenoids is conto toe contact 63 which is carried by the contactor arm The contact finger 64 is in turn con to that terminal of the main switch is opposite to that to 20 is connected.

4 disc 28 and explane of this trip coils 67 connected in 'erininal 66 of the solenoids ct finger 6% in such manner tute a lay-pass across the inof the contact 63 and the contacting r 64: cooperatin; therewith. (lpcrativel v ociatcd with the trip coils 6'? is a magnetic he per 68 pivoted at 69 upon th hearing sore .3 76. This keeper 68 pro- .t its lower end with a laterally exndine POli on T1 through which projects the lower end of the reset rod 52. As most clearly appears in Figures 1 and 2, the portion of the rod 52 which projects through the shelf 71 is of reduce-d cross section such that by lowerii j the rod 52, the keeper 68 will be swung away from the trip coils 67. Pivotally secured to he upper end of the k eper ()8 and extendin horizontally across the bottom edge of the disc 28 is an actuating bar 72 for actuating the trip pin release member 39. The rear portion of this actuating bar 72 is of reduced vertical cross section for the purpose of permitting; the trip pin release member 39 to pass freely thereover when the trip coils 6'? are in (lo-energized condition. However, when the trip coils 67 are energized the keeper 68 will he moved to the Fig. 2) with the result that the the actuating: bar which is of ertical cross section will be inter- "ectlv in the path of movement of the trip n release member 39 whereby the latter will be lifted out of the notch d0 to disc are a series betw 56 and .ihe cothat they coi terlock consist permit the vardly beyond the front face of the operating disc in ore-r t n onrating disc 28 being coupled to the synchronous operator 10 will operate at synchronous speed, and that by relatively adjusting the members 30 and 31 of the coupling device 26 the apparatus may be set to operate at any point of the current cycle. It is to be further understood that the synchronous operator operates from the same source of supply which furnishes power for lighting the lamps or whatever other devices are to be used. Figures 7, 8, 9 and 10 are diagrammatic views showing the several circuit arrangements in relation to the controller drum, which latter is shown in development plan section. Still further it will be seen both from Figure 1 and from Figure 7 that all of the lower terminals of the several banks of lamps are connected to one terminal of the main power supply switch 25 and that the opposite terminals of these banks of lamps are connected respectively to one set of main contact and transfer contact fingers and 2+l, there being seven such sets employed in this particular instance. Inasmuch as each of the seven banks of lamps is controlled by its respective set of fingers 2S and 2st in substantially the same manner, the O}lO1l1tlU}1 of only one of these sets will be hereinafter described.

In nigure 1 the several circuits A, B, C and D may be readily followed by the arrows showing the direction of current flow, these circuits being shown even more clearly in Figures 7-10, inclusive. Referring to Figures 1 and 8, it will be seen that the first circuit which is established as the controller drum 11 revolves about its axis in the direction of the arrow, is that designated by the reference character A. This circuit A supplies current from one of the positive terminal of the switch 25 to the contact finger 20, thence to the conductor ring lei and to one of the bars 16 (only the lower left hand bar 16 will be considered, this bar and its associated transfer and circuit control bars 17 and 18, respectively, being operable to control the left hand bank of lamps 12) hence to the contact finger and through the bank of lamps 12 connected to said contact finger, to the opposite terminal of the switch (See circuit A in Figure 8.)

Just before the finger leaves the main contact bar 16 with which it has been in contacting engagement, the next adjacent transfer contact finger 24 will have come into contact with the transfer bar 17 next adjacent the bar 16, and when the finger 2 finally leaves the bar 16 a second circuit B will he established as follows :-from the positive terminal of the switch to one of the contact terminals 54:, across the bridging; member 55 to the other terminal 5i, thence to the finger 21 and conductor ring 15, thence to the transfer bar 17 and its contacting finger 24, and finally through the bank of lamps 12 to the opposite terminal of the switch 25. (See circuit B in Figure 9.)

Now, just prior to the instant that the finger 24 leaves its transfer bar 17, the extreme right hand finger 22 will come into contact with rcuit control contact bar 18 which is sly associated with said bar 17, and a third circuit CD will be established as follows: from the positive terminal of the switch25 to the finger 20, thence to the conductor ring 14, thence to said circuit control contact bar 18, thence to the contact finger 22, thence through the solenoids 56 and finally through the solenoids 67 to the opposite terminal of the switch 25. i

l "station of the solenoids 67 results in a on of the actuating bar 72 to lift the trip pin release member 39 whereby to permit the trip pin 84 to be projected transversely through the rotating disc 28. As this disc roa es it carries the projecting trip pin with it sr ii that the latter engages the depending branch 49 of the bell crank lever 43 to force ctor arm 44 to the left against the aci of the spring 45. In so moving to the l i this arm 44 causes the circuit breaker 54:;-55 to open and at the same time brings the contact 63 into engagement with the contact in ger 64 to short circuit and so deenergize the solenoids 67. Inasmuch as the solenoids 56 i .ve also been energized the keeper 57 will be pulled down so that its catch 61 engages the catch 62 on the contactor arm 44 to maintain the latter in out-of-normal position. At the same time that the branch 49 of the crank lever 4.3 is raised upwardly the other branch thereof lowered with the result that as the reset rod 52 swings the magnetic keeper away from the solenoids 67 the actuating 2 pulled into inoperative position to :t the member 39 to seat once more in the notch when the trip pin 34 is forced into retracted position by the action of the inclined ramp 41'.

It will thus be apparent that the current will flow from the terminal 66 of the solenoids 56 through the electrical interlock 63G4 directly back to the negative terminal of the main switch 25. Inasmuch as the main circuit breaker 54-55 will have been actuated at the instant when the current passes throu h or near the zero point of the cycle there Wlll not have been occasioned at any time any of the objectionable arcing which it is the object of this invention to eliminate. By suitably setting the index 33 against any portion of the scale 32 of the adjustable coupling device 26 the point in the current cycle at which it is desired to operate the main circuit breaker can be nicely determined.

As most clearly appears in Figures 2, 3 and any number of main contactor arms 44 may be employed to control a corresponding number of controller drums, all of these arms being mounted freely upon the common shaft 42 for actuation by a single bell crank lever 43. For each contactor arm employed there is provided a pair of solenoids 56, but regardless of the number of arms only one unit consisting of the rotating disc 28 and the trip pin control mechanism (34, 39, 72, 68, 67) is necessary. It is to be understood that various changes may be made in the mechanisms described without departing from the principles of the invention and it is accordingly desired to claim the same broadly as Well as specifically as indicated by the appended claims.

What is claimed as new and useful is 1. An alternating current circuit controlling mechanism comprising, in combination, a synchronous operator, a disc arranged for rotation by said operator at synchronous speed, a trip pin arranged for projection transversely through said disc, and means for maintaining said trip pin in retracted position.

2. An alternating current circuit controlling mechanism comprising, in combination, a synchronous operator, a substantially vertically disposed disc operable with said operator at synchronous speed, a trip pin arranged for project-ion transversely through said disc, and means permltting said pin to be project- .ed outwardly beyond one face of said disc.

3. An alternating current circuit controlling mechanism comprising, In combination, a synchronous operator, a member rotatable in a substantially vertical plane said member being coupled to said synchronous operator, a trip pin arranged for projection beyond one face of said disc, and means disposed to one side of, but associated with, said disc to automatically force said trip pin into retracted position.

4. An alternating current circuit controlling mechanism, comprising a synchronously driven element, a circuit breaker mechanism, a trip pin arranged adjacent the peripheral edge of said element, means for causing said pin to be projected transversely beyond one face of said element, and means operably associated with said pin whereby to permit the latter, when in outwardly projected position, to actuate said circuit breaker.

5. An alternating current circuit controlling mechanism, comprising a rotatable member operable at synchronous speed, a stub shaft arranged to one side and extending transversely of said member, a main contactor arm carried freely upon said shaft, a lever fixed to said shaft, interengaging means on said lever and contactor arm, and means carried by said rotating disc and arranged to engage said lever whereby to actuate said contactor arm, through said interengaging means.

6. An alternating current circuit controlling mechanism comprising a member operable at synchronous speed or at any fractional or prime multlple of said speed, a controller mechanism operable to control the circuits of one or more translating devices, said mechanism including a plurality of sets of contact bars, and means operatively associated with said member and controller mechanism for transferring the current sequentially from one set of said bars to another whereby to alter the e 'ieting circuit condition at a predetermined instant in the current cycle.

7. in alternating current circuit mechanism for controlling a plurality of circuits, comprising a synchronous operator, a mechanism for establishing said circuits in definite sequence, and means operatively associated with said synchronous operator for altering the existing condition in each circuit at predetermined instants in the current cycle.

8. in alternating current circuit controlling mechanism comprising a means for controlling one or more circuits, said means including a plurality of sets of contact bars and a plurality of lingers operatively associated with each of said sets, means for transferring said circuits from one of said sets of contact bars to the other without disturbing the electrical continuity of the circuits, and means for interrupting said continuity in each circuit when the current value in the circuit to be interrupted is of a predetermined value.

9. An alternating current circuit controlling mechanism for controlling one or more electrical circuits comprising, in combination, a controller drum including a contact bar for each circuit, a transfer bar for each contact bar and a circuit control contact bar for each transfer bar, means for transferring each circuit from its contact bar to its respective transfer bar without disturbing the electrical continuity of said circuit, and means for transferring said circuit from said transfer bar to its respective circuit control contact bar at a predetermined instant in the current cycle.

10. An alternating current circuit control- I ling mechanism for controlling one or more to the instant that the next preceding finger is removed from contact with its respective bar, and means for sequentially transferring each circuit from its contact bar to its transfer bar and thence from the latter to its cirjcuit control contact bar whereby to open said circuit when the current is of substantially zero value.

11. An alternating current circuit controlling mechanism comprising, in combination,

'a synchronous operator, a multipleicircuit controller drum, an element associated with said drum and forming part of one of several circuits, a second element associated wlth said drum, means for transferring said circuit to said second element without interrupting the electrical continuity of said circuit, a circuit breaker arranged to be included in said transferred circuit, and means controlled by said synchronous operator for operating said circuit breaker to open said circuit at a predetermined instant in the current cycle.

12. An alternating current circuit controlling mechanism comprising, in combination, a synchronous operator, means for control ling an electrical circuit including a contact bar, a transfer bar and a circuit control bar for each circuit, means for transferring said circuit from said contact bar to said transfer bar without interrupting the electrical con tinuity of said circuit, a circuit breaker arranged in series with said transfer bar, leans operable by said synchronous operator for actuating said circuit breaker at a predetermined instant in the current cycle, and means operable simultaneously with said last mentioned means for transferring said circuit from said transfer bar to said circuit contact bar.

13. An alternating current switch for conu trolling a circuit comprismg a synchronous operator, means including a plurality of sets of electrical contact elements for transferring said circuitfrom one of said sets to another in a definite sequence, and means operatively associated with said synchronous operator for altering the existing condition in the circuit as finally established at a predetermined instant in the current cycle.

In testimony whereof we hereunto aflix our signatures.

FREDERICK V. LEE. MYRICK V. PULLEN. 

